The pilot approached and descended towards the west over power lines adjacent to the east/west corn field that he was going to spray. He noted that the sun was "kinda bright" and was a restriction to visibility. During the round out to level flight over the field, the pilot noticed that the airplane continued to sink and before he could release the spray handle and actuate the dump handle, the airplane impacted the field. The pilot "thinks" that his left hand went from the spray lever to the power lever to both hands on the control stick to try and keep the wings level to avoid the airplane from nosing over. The pilot stated that the field "appeared" to be flat but was later told that it had a "slight" rise.